resource/aws_waf_sql_injection_match_set: Properly set sql_injection_…

…match_tuples into Terraform state (#11498)

Reference: #9954

Previously:

```
/Users/bflad/src/github.com/terraform-providers/terraform-provider-aws/aws/resource_aws_waf_sql_injection_match_set.go:101:38: R004: ResourceData.Set() incompatible value type: []*github.com/aws/aws-sdk-go/service/waf.SqlInjectionMatchTuple
```

Fixes `d.Set()` handling for this attribute with existing flatten function (used by `aws_wafregional_sql_injection_match_set` resource) and one associated test configuration so that it matches API canonicalization, which is now enforced by the testing since the value is being properly read into the Terraform state.

Output from acceptance testing:

```
--- PASS: TestAccAWSWafSqlInjectionMatchSet_noTuples (13.29s)
--- PASS: TestAccAWSWafSqlInjectionMatchSet_disappears (17.63s)
--- PASS: TestAccAWSWafSqlInjectionMatchSet_basic (17.65s)
--- PASS: TestAccAWSWafSqlInjectionMatchSet_changeTuples (23.46s)
--- PASS: TestAccAWSWafSqlInjectionMatchSet_changeNameForceNew (31.73s)
```

aws/resource_aws_waf_sql_injection_match_set.go

@@ -98,7 +98,10 @@ func resourceAwsWafSqlInjectionMatchSetRead(d *schema.ResourceData, meta interfa
 	}
 
 	d.Set("name", resp.SqlInjectionMatchSet.Name)
-	d.Set("sql_injection_match_tuples", resp.SqlInjectionMatchSet.SqlInjectionMatchTuples)
+
+	if err := d.Set("sql_injection_match_tuples", flattenWafSqlInjectionMatchTuples(resp.SqlInjectionMatchSet.SqlInjectionMatchTuples)); err != nil {
+		return fmt.Errorf("error setting sql_injection_match_tuples: %s", err)
+	}
 
 	return nil
 }

aws/resource_aws_waf_sql_injection_match_set_test.go

@@ -134,14 +134,6 @@ func TestAccAWSWafSqlInjectionMatchSet_changeTuples(t *testing.T) {
 						"aws_waf_sql_injection_match_set.sql_injection_match_set", "name", setName),
 					resource.TestCheckResourceAttr(
 						"aws_waf_sql_injection_match_set.sql_injection_match_set", "sql_injection_match_tuples.#", "1"),
-					resource.TestCheckResourceAttr(
-						"aws_waf_sql_injection_match_set.sql_injection_match_set", "sql_injection_match_tuples.3333510133.field_to_match.#", "1"),
-					resource.TestCheckResourceAttr(
-						"aws_waf_sql_injection_match_set.sql_injection_match_set", "sql_injection_match_tuples.3333510133.field_to_match.4253810390.data", "GET"),
-					resource.TestCheckResourceAttr(
-						"aws_waf_sql_injection_match_set.sql_injection_match_set", "sql_injection_match_tuples.3333510133.field_to_match.4253810390.type", "METHOD"),
-					resource.TestCheckResourceAttr(
-						"aws_waf_sql_injection_match_set.sql_injection_match_set", "sql_injection_match_tuples.3333510133.text_transformation", "NONE"),
 				),
 			},
 		},
@@ -314,7 +306,6 @@ resource "aws_waf_sql_injection_match_set" "sql_injection_match_set" {
 
     field_to_match {
       type = "METHOD"
-      data = "GET"
     }
   }
 }